10 kV小电阻接地系统单相接地故障时的跨步电压仿真与实验研究

摘要

围绕某市10 kV配网改消弧线圈接地为小电阻接地系统的工程,对馈线首末端发生单相接地故障时的接地故障电流进行了计算分析.采用四层土壤模型,对馈线发生单相直接对地短路时的跨步电压分布进行了有限元仿真计算；并对馈线首末端均发生单相直接对地短路以及单相经横担对地短路时的跨步电压进行了实验研究.仿真与实验结果的对比表明两者基本保持一致.最后提出了降低跨步电压对人身安全的威胁的措施.%The current of single-phase grounding fault at feeder end is analyzed for a 10 kV urban system earthed with low resistance.With the four-layer soil model,the distribution of step voltage is simulated by FEM (Finite Element Method) analysis software for the single-phase direct grounding fault of feeder,while the step voltage is tested for the single-phase direct or cross-arm-passed grounding fault at both ends of feeder.The simulative results are basically consistent with the test results.Countermeasures against the fatalness of step voltage to human safety are given.